North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: IGPs in use
[email protected] (Vince Fuller) writes: > There are some drawbacks to IS-IS: ... > > IS-IS uses an underlying traffic exchange which is based on OSI/CLNS. This > introduces requirements for OSI addressing and CLNS implementation which are > otherwise useless in an IP-centric network. IMHO, this represents a > substantial bit of operational complexity (obtaining CLNS addresses, teaching > operations/engineering staff how to use them and interpret them while > debugging, etc., etc...) While it does require OSI addressing, it does not require CLNP forwarding. As to the engineering and operations aspects, the additional complexity can, with a reasonable implementation, be almost completely hidden. For example: > show isis adjacency IS-IS adjacency database: Interface System L State Hold (secs) SNPA fxp0.0 lab5 2 Up 16 0:0:c0:cc:a0:bf fxp0.0 lab2 2 Up 25 0:0:c0:e8:69:db fxp0.0 lab10 1 Up 22 0:a0:c9:36:b3:a6 > On a pragmatic note, though, the relative successes of IS-IS and OSPF in the > large provider marketplace probably has more to do with the relative competence > of the cisco's original OSPF and IS-IS implementors than anything else > (only someone else who suffered through OSPF's growing pains way back in > the 9.0-9.1 days can really appreciate this comment...) Very true, tho those of us who had ringside seats do sympathize. ;-) Tony
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